What are the 3 main features of a “quality backlink”?

A quality backlink is editorially placed, meaning it's naturally earned and integrated into content because it provides value, not because it was bought or forced. Relevancy is crucial; the linking page and domain should be topically related to your content, signaling to search engines that the link is meaningful. High website and page authority from the linking domain indicates that the source is trusted and reputable, passing on more "link equity" to your site. Links in a website footer are often considered less valuable or even spammy due to their non-editorial nature. While guest posts can generate quality backlinks, the mere act of guest posting doesn't guarantee quality; the link still needs to meet the other criteria of editorial placement, relevancy, and authority.